This relates to imaging systems and, more particularly, to imaging pixels with shielded floating diffusions nodes.
Modern electronic devices such as cellular telephones, cameras, and computers often use digital image sensors. Imagers (i.e., image sensors) may be formed from a two-dimensional array of image sensing pixels. Each pixel receives incident photons (light) and converts the photons into electrical signals. Image sensors are sometimes designed to provide images to electronic devices using a Joint Photographic Experts Group (JPEG) format.
With typical image sensing pixels, metal lines associated with floating diffusion nodes form parasitic capacitances with other metal lines in the pixels. These parasitic capacitances increase the overall capacitance of the floating diffusion nodes, thereby decreasing the pixel conversion gain of the pixels and reducing the sensitivity of the pixels to incident light.
It would therefore be desirable to provide improved imaging pixels with floating diffusion nodes with reduced parasitic capacitances.